Optical quality of intraocular lenses

The ANSI Z80.7 standard for intraocular lens quality is being updated. This paper identifies areas that require revision and suggests that a clear distinction between the lens design and the quality control test methods be made. The standard monofocal lens design consists of two spherical surfaces, and lens power can be specified by the thick lens equation, using body temperature refractive index values at a wavelength of 550 nm. Interferometry might be used as a primary manufacturing test method for poly(methyl methacrylate) lenses; tolerance values for lens surface errors are suggested. Other test methods can also be used. Measuring the modulation transfer function in fluid may be the most useful.